Process of treating masses of concrete.



CARLETON ELLIS, F MONTCLAIR, NEW JERSEY, ASSIGNOR .TO NEW JERSEYTESTIQ'G LABORATORIES, A CORPORATION OF NEW JERSEY.

PROCESS OF TREATING MASSES OF CONCRETE.

No Drawing.

To all whom it may concern:

Bevit known'that l. CARLn'roN Ennis, a citizen of the United States, anda resident of Montclair, in the county of Essex and- State of NewJersey, have invented certain new and useful Processes of TreatingMasses of Concrete, of which the following is a specification.

This invention relates tov a method of treating cement or concretesurfaces and relates in particular to the treatment of conforts havebeen made to overcome the diffi- 'culty, but without satisfactoryresults.

The usual method is to flood the surface with a hard varnish so thetafilm of the dried varnish surfaces the concrete. Owing to the lack ofresiliency of concrete such a surface even if secured by the use ofseveral coats of very hard drying varnish, is easily abraded. WVaterglass, fluosilicates, and various drying oils have been used withoutsatisfactory elimination of dusting.

Floor concrete usually is given a troweled surface or granolithic effectand the finishing coat is generally of high cement and low sand content.I Also by troweling the finer particles of cement and sand work towardthe surface while the coarser particles sink beneath. '7 This results ina glazed or smooth surface to which varnish coatings do not clingreadily and the density of the extreme surface layerprevents penetrationof the varnish to any great extent. Such coatings readily peel andrepainting or recoating is soon required.

In the present invention the surface of the concrete mass is left opento secure proper penetration of the coating or as this IS oftenimpracticable the troweled or granolithic finish is etched with acid andthe like after setting or washed with water'j ust after the initial setand before the final set, orin other waysroughened so that the surfaceof nearly neat cement is evenly etched or "opened so as to permit of thesubsequent treatment. After drying such an opened Specification ofLetters Patent.

Patented Mar. 9, 1915..

Application filed September 25, 1911. Serial No. 651,185.

surface the coatin material is lied. The first coat shouldfim ratherthinin ody, preferably, so as to secure a substantial anchoringfoothold. Subsequently one or more coats of the material are applied tobuild up a stratum in and around the particles of concrete or cementwhich has a mean height substantially that of the average height of theprojecting ranules or rugosities of the roughened sur ace. Thus severalimportant advantages are secured by this procedure. First, the coatingis securely anchored to the surface; second, the peaks In carrying outmy invention I prefer-- ably as stated roughen the surface of theconcrete mass with acid, using for example a five or ten per cent.solution of hydrochloric acid, or a fifteen per cent. solution of sodiumbisulfate, or similar acid wash. A mixture of three parts of sodiumbisulfate"to one part of magnesium chlorid is useful, as roughening issecured without material weakening of the bonding of the set cement.This mixture is used in about the proportion of one and one half oundsto the gallon of water. These rougffening washes are al lowed to remainon the surface until the desired degree of rugosity'is secured, when thesurface is washed and dried. The surface is now ready to be treated withthe coating or impregnating waterproofing or hardening material. Theselection of the material for this purpose depends to some extent on theservice to which it is to be put. For oflice buildings and the like of agenerally dry character a short oil varnish may be used.' This may berepared from copal gum, such as'Ma-nila, auri, Zanzibar, Pon-' tianak,Borneo and the like, with wood oil or other drying oil capable ofproducing a tough film with varnish gum after suitable heat treatment.or Pontianak rubber resin maybe used with a drying oil, with orwithused, although this material has certain disterials.

out additions of the resins mentioned. As Pontianak rubber resin issubstantially unsaponifiable it is well adapted for such uses, as it isnot affected by cement alkali. However under the present invention thereis no longer need of using expensive hard gums and oils for surfacetreatment, as the rugosities of the surface protect the waterproofingfilm from material abrasion for a long time. Muchcheaper materials, suchas solutions of Pontianak rubber resin or Manila resin and the like in ahydrocarbon solvent may be used; and although more brittle than the oilvarnishes they are sufficiently protected by the rugosities so that theyare preserved from abrasion for an indefinite time. A small amount ofceresin or paraffin wax or other waxy body gives a slight temperingeffect without materially affecting the cost. Larger amounts soften theresins considerably and in such cases the rugosities are made quiteprominent, so that the softer material is better protected.Tetrachlornaphthalene and also pentachlornaphthalene are extremely goodwaterproofing agents and when mixed with resins in about equalproportions and suitably thinned form a dust preventing andwaterproofing material which is excellent for mill floors and fac-vtories where dampness prevails, or where acids or other chemicalreagents are employed.

As stated, the first coat should preferably be of'thin consistency so asto secure effective penetration and form an anchoring layer. Subsequentcoats are better applied of heavier body so as to quickly fill thedepressions to practically the level of the surface peaks, orthereabout. Various pigments may be used in the floor coatings as wellas the usual filling. andextending ma- The addition 7 of rather coarselyground silex,-pumice and the like secures greater frictional foothold.Pulverized alundum is especially satisfactory in this respect, as asmall quantity serves for a .large surface and the attritional or frictional reinforcement to the peaks of natural origin obtained in this wayis extremely useful in'floors subjected to extreme service conditions.Carborundum also may be advanta es which do not appear with alundum ansimilar artificial peak-formers.

Instead of using surface filling materials of a varnish character, othercompositions may be used, as for example, a mixture of zinc oxid andzinc chlorid, or of magnesium oxid and chlorid, preferably admixed withartificial peak-forming material of an extremely hard nature. Forexample the surface may be treated with zinc oxid and alundum in waterwhich has been bodied with a little alkali-casein and after drying aconcentrated solution of zinc chlorid is applied.

A zinc oxychlorid cement forms and as soon as this has set the surfacemay be washed and dried. If desired a coating of varnish may be appliedover this.

The condensation products of carbolic acid other cresolor other phenolmay some time be employed to good advanta e, especially when the cementis nammfi rough and open and has not been etched -with acid.Condensation products made with either and acid or alkaline condensin orcatalytic agent may be employed and i desired the surface, after coatingor impregnation, may be heated to superficially form a hard, infusible,condensation product of great durability.

If the cement flooring or its upper layers carry a Waterproofing agentof the integral stantially to a level with the peaks thereof,

with a dust-preventing and waterproofing material; whereby the wear istaken substantially by said peaks.

2. The process'of treating-masses of concrete which comprises rougheninga surface thereof in impregnating such surface with a water-resistantbinding material and infilling the depressions of said surfacesubstantially-to a level with the peaks thereof, with a dust-preventingand waterproo terial of a finish coating character; whereby the wear istaken substantially by said peaks.

3. The process of treating masses of concrete which comprises rougheninga surface thereof in impregnating such surface with a water-resistantmaterial as an anchdring coat or layer and in filling the depressions ofsaid surface substantially to a level with peaks thereof, with amaterial of a dustpreventing and waterproofing Y character, carrying anextremely hard granular abrasive serving as frictional material; wherebythe wear is taken substantially by said peaks.

4. The process of treating masses of concrete and similarmaterial usedfor fiooring purposes which comprises roughening the surface thereof byremoval of very fine cement material and consequent exposure of coarseraggregate and sand grains, in su rficially impregnating .the roughenedsur ace thereof. with a water-resistant material as an anchoring layer,and in fillin the depressions of said surface substantlally to a levelwith the rugosities thereof, but no higher, with a dust preventing andwaterproofing binding material of an organic character; whereby the wearis taken substantially by said peaks. 7

5. The process of treating masses of concrete which comprises rougheningandsuperficially impregnating a surface thereof with a water-resistantbinding material and in filling the depressions of said surfacesubstantially to a level with the peaks thereof, wi a dust preventingand waterproofing material of a finish coating character;

whereby the wear is taken substantially by said peaks.

Essex and State of New Jersey, this 22nd day of September, A. D. 1911.

CARLETON ELLIS. Witnesses: v

.RoBT. M. HENING, EmzABErir M. MARTIN.

